Other Endocrine Organs Regulated by Hypothalamus-Pituitary Axis

Hypothalamus - Pituitary - Thyroid axis

A model that can be applied to other endocrine glands.

Hypothalamus - Pituitary - Adrenal axis

Hypothalamus ————> Pituitary ————> Adrenal cortex ————> Target organs; involves CRH, ACTH, and Cortisol.

Hypothalamus - Pituitary - Gonadal axis

Hypothalamus ————> Pituitary ————> Gonads ———————> Target organs; involves GnRH, LH/FSH, and Estrogens/Androgens.

Hypothalamus - Pituitary - Liver axis

Hypothalamus ————> Pituitary ————> Liver ————————> Target organs; involves GHRH, GH, and IGF-I.

Endocrine disorders

Fall broadly into three categories: Hyperactivity, Hypoactivity, and Inappropriate activity.

Hyperactivity

Excess secretion of the hormone or hypersensitivity by target cells.

Gigantism

A condition caused by hyperactivity leading to excessive growth.

Acromegaly

A condition caused by hyperactivity leading to enlarged features.

Hypoactivity

Insufficient secretion of the hormone or inadequate reaction by target cells.

Dwarfism

A condition caused by hypoactivity leading to short stature.

Diabetes mellitus

A condition characterized by insufficient insulin secretion or action; includes Type I and Type II diabetes mellitus.

Inappropriate activity

Unregulated secretion from the wrong source and/or at the wrong time.

APUDomas

Tumors that can cause inappropriate ectopic secretion of hormones, leading to diseases such as Cushing's Syndrome or acromegaly.